Tubular ligament cutting implement

ABSTRACT

A cutting implement includes a first tubular portion and a second tubular portion. Each tubular portion is hollow and includes a blade element at a distal end. The blade element helps define an aperture that allows access to the interior hollow portion of the tubular portion. A ligament graft element is threaded through the aperture of each tubular portion and the respective tubular portions are interoperated to cut the ligament graft.

PRIORITY APPLICATION

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 13/493,320 ('320 application) filed Jun. 11, 2012.The contents of the '320 application are herein incorporated byreference in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to a cutting instrument adapted to help asurgeon harvest a replacement tendon for an anterior cruciate ligament(ACL) injury from the quadriceps tendon.

BACKGROUND

Most people can go through the majority of their life without everappreciating the complicated structure of the knee that helps them walk.However, the knee remains a fragile mechanical structure that is readilysusceptible to damage. While medical advances have made repairing theknee possible, repair of certain types of injuries results in other longterm effects. To assist the reader, FIG. 1 is provided with a briefexplanation of the components of the knee.

For the purposes of the present disclosure, and as illustrated, the kneemay be composed of the quadriceps muscles 10, the femur 12, thearticular cartilage 14, the lateral condyle 16, the posterior cruciateligament 18, the anterior cruciate ligament 20, the lateral collateralligament 22, the fibula 24, the tibia 26, the patellar tendon 28, themeniscus 30, the medial collateral ligament 32, the patella 34 (shownslightly displaced to the side—it normally rests in the center of theknee) and the quadriceps tendon 36. Of particular interest for thepurposes of the present disclosure is the anterior cruciate ligament(ACL) 20 and what is done to repair the ACL 20.

ACL tears are common in athletes and are usually season ending injuries.The ACL 20 cannot heal—it must be surgically reconstructed. Thereconstruction requires replacement tissue. The most common tissue usedis a central slip of the patient's own patellar tendon 28. In practice,the patellar tendon 28 has proven to be generally effective, but thesize of the graft that can be used is limited to the size of thepatient's own patellar tendon 28. As a rule of thumb, only a third ofthe patellar tendon 28 may be harvested as a graft. Thus, a doctor willmeasure the width of the patellar tendon 28, divide by three, and takethe middle third of the patellar tendon 28. Such harvested grafts arerarely more than 10 mm wide and may be smaller. Taking this tissue froma person's patellar tendon 28 also causes significant pain anddiscomfort in the post operative healing period, which may last up to ayear, and up to twenty (20) percent of these patients are left withchronic anterior knee pain.

Some doctors recommend and use other graft sources, such as cadavergrafts, but cadaver grafts have a higher failure rate. Additionally,there is a non-zero chance of disease transmission or rejection by thepatient's immune system. As a final drawback, cadaver grafts are usuallyquite expensive and may not be covered by some insurance companies.

Other doctors use hamstring tendons (e.g., the distal semitendinosustendon) because the scar created during harvesting is relatively smalland there is less pain during the rehabilitation, but again, thehamstring tendon has its own collection of disadvantages. Thedisadvantages include the fact that once the graft is taken, a patient'shamstring will never recover to its previous strength. Further, allhamstring reconstructions stretch and are looser than the original ACL20. This loosening is particularly problematic in younger femaleathletes.

Another alternative graft source is the quadriceps tendon 36. Thequadriceps tendon 36 is larger and stronger than either the patellartendon 28 or the hamstring tendon. The quadriceps tendon 36 is likewisestiffer and less prone to stretching or plastic deformation. However,the qualities that make the quadriceps tendon 36 attractive alsocontribute to the difficulty in harvesting a graft from the quadricepstendon 36. Existing surgical implements require a large incision up thelongitudinal axis of the femur 12 on the front or ventral/anterior sideof the thigh to cut down to the level of the quadriceps tendon 36,resulting in a large post operative scar. Additionally, the quadricepstendon 36 has a consistency similar to the proverbial shoe leather,making it difficult to cut. However, an ACL 20 repaired with grafts fromthe quadriceps tendon 36 generally results in almost no anterior kneepain postoperatively over the short or long term and recovers quicker.

The present inventor's prior application, U.S. patent application Ser.No. 13/102,562 ('562 application), filed May 6, 2011 (which is herebyincorporated by reference in its entirety), provides a number of devicesdesigned to create a graft from the quadriceps tendon 36 and disclosesan element to make the initial cut on the quadriceps tendon 36 as wellas a number of secondary cutting implements to trim the distal end ofthe graft. While these secondary cutting implements are adequate toperform their intended purpose, alternate devices may be more costeffective or have easier engineering realities. The previouslyincorporated '320 application also provides suitable secondary cuttingimplements, but again, alternate devices may be more cost effective, bemore efficacious at cutting, or have easier engineering realities.

SUMMARY

The present disclosure provides a secondary cutting implement that isadapted to trim a distal end of a preliminarily harvested graft from thequadriceps tendon in a minimally invasive manner. Once the quadricepstendon graft is secured, it may be used in conventional manners torepair the anterior cruciate ligament (ACL).

The secondary cutting implement comprises a first hollow tubular elementand a second hollow tubular element that telescopingly fits within thefirst tubular element. The distal ends of each tubular element includean interior blade element positioned perpendicular to a longitudinalaxis of the tubular element. The interior blade elements are sized suchthat the distal end of each tubular portion is at least partially open.That is, the blade elements help define an aperture at the distal end ofthe tubular hollow elements.

In use, the quadriceps tendon is cut to a desired length and then thegraft portion is threaded through the open distal end of the firsttubular element. The graft portion is also threaded through the opendistal end of the second tubular element. The tubular elements arerotated in opposite directions causing the interior blade elements totrim the distal end of the graft.

An additional embodiment differs in that only a single one of thetubular elements has a blade. Likewise, the distal ends of the tubularelements include a cutaway or notch that facilitates insertion of thebone plug portion of the graft as the graft is threaded through the opendistal end. Additionally, a third tubular element may be included thatupon insertion closes the cutaway or notches in the first and secondtubular elements to improve cutting when the notches are partiallyaligned.

While the present disclosure focuses on the use of the tubular cuttingimplement in the context of cutting quadriceps tendons for repairing ACLinjuries, the present disclosure is not so limited, and the tubularcutting implement may be used in other sorts of procedures.

Those skilled in the art will appreciate the scope of the disclosure andrealize additional aspects thereof after reading the following detaileddescription in association with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thisspecification illustrate several aspects of the disclosure, and togetherwith the description serve to explain the principles of the disclosure.

FIG. 1 illustrates a conventional knee;

FIG. 2 illustrates an exploded perspective view of an exemplaryembodiment of the secondary cutting implement of the present disclosure;

FIGS. 3A-3F schematically illustrate operation of the secondary cuttingelement;

FIG. 4 illustrates a flow chart describing the operation of thesecondary cutting element;

FIG. 5 illustrates an exploded perspective view of an exemplaryembodiment of the secondary cutting implement of the present disclosure;

FIG. 6 illustrates a side view of the secondary cutting implement ofFIG. 5;

FIG. 7 illustrates a perspective close up of the cutting end of thesecondary cutting implement of FIG. 5;

FIG. 8 illustrates a side close up of the cutting end of the cuttingimplement of FIG. 5; and

FIG. 9 illustrates a top close up of the cutting end of the cuttingimplement of FIG. 5.

DETAILED DESCRIPTION

The embodiments set forth below represent the necessary information toenable those skilled in the art to practice the disclosure andillustrate the best mode of practicing the disclosure. Upon reading thefollowing description in light of the accompanying drawings, thoseskilled in the art will understand the concepts of the disclosure andwill recognize applications of these concepts not particularly addressedherein. It should be understood that these concepts and applicationsfall within the scope of the disclosure and the accompanying claims.

FIG. 2 illustrates a first exemplary embodiment of a secondary cuttingimplement 50 according to the present disclosure. The secondary cuttingimplement 50 is useful for trimming a graft (e.g. graft 80 explainedbelow) being harvested from the quadriceps tendon 36, such as occurswhen the cutting implement of the previously incorporated '562application is used to cut a graft from the quadriceps tendon 36. Thesecondary cutting implement 50 has a first element 52, which is hollowand has a first handle end 55 and a first distal end 56. The firstdistal end 56 includes a first blade element 58. The first blade element58 is positioned perpendicular to a longitudinal axis 60 of the firstelement 52. The first blade element 58 may be integrally formed with thebody of the first element 52 or fixedly secured thereto. In an exemplaryembodiment, the first element 52 is adapted to be reusable while thefirst blade element 58 is removably affixed thereto such that it can bereplaced readily. Thus, the first blade element 58 may be considereddisposable or reusable as desired. The first blade element 58 extends,in an exemplary embodiment, approximately halfway across first distalend 56 (e.g., covering approximately 45-55% (and in an exemplaryembodiment approximately 51%) of the area of the first distal end 56)and partially defines a first aperture 62 through which a graft may bethreaded as explained in greater detail below. In an exemplaryembodiment, the first element 52 is made from a metal such as surgicalstainless steel (e.g., made out of chromium, nickel, molybdenum, and/ortitanium) such as 316L, 316LVM and/or compliant with ASTM F138. In analternate embodiment, the first element 52 is made from a polymer basedmaterial. The first blade element 58 may be made from surgical steel,glass, obsidian, diamond, or the like as desired. In an exemplaryembodiment, the first element 52 may be approximately 100 mm long.

The second element 54, which is hollow and has a second handle end 64and a second distal end 66. The second distal end 66 includes a secondblade element 68. The second blade element 68 is positionedperpendicular to a longitudinal axis 70 of the second element 54. Thesecond blade element 68 may be integrally formed with the body of thesecond element 54 or fixedly secured thereto. In an exemplaryembodiment, the second element 54 is adapted to be reusable while thesecond blade element 68 is removably affixed thereto such that it can bereplaced readily. Thus, the second blade element 68 may be considereddisposable or reusable as desired. The second blade element 68 extends,in an exemplary embodiment, approximately halfway across second distalend 66 (e.g., covering approximately 45-55% (and in an exemplaryembodiment approximately 51%) of the area of the second distal end 66)and at least partially defines a second aperture 72 through which agraft may be threaded as explained in greater detail below. In anexemplary embodiment, the second element 54 is made from a metal such assurgical stainless steel (e.g., made out of chromium, nickel,molybdenum, and/or titanium) such as 316L, 316LVM and/or compliant withASTM F138. In an alternate embodiment, the second element 54 is madefrom a polymer based material. The second blade element 68 may be madefrom surgical steel, glass, obsidian, diamond, or the like as desired.In an exemplary embodiment, the second element 54 may be approximately120 mm long and 23 mm in interior diameter. The first element 52 may besized such that its interior diameter is just large enough to fit aroundthe exterior diameter of second element 54.

By design, the first element 52 is shorter than the second element 54,and the second element 54 telescopingly fits within the first element 52such that the second handle end 64 extends out past the first handle end55 so as to facilitate manipulation of the second element 54 within thefirst element 52.

In an exemplary embodiment, the handle ends 55 and 64 may be abraded,knurled, or otherwise textured to provide a firm gripping surface. In analternate embodiment, there may be an explicit handle attached to orformed on the handle ends 55 and 64 to make manipulation and grip morenatural.

FIGS. 3A-3F illustrate a technique of using the secondary cuttingimplement 50 as further explained in the flowchart of FIG. 4. Theprocess 100 of harvesting the graft 80 begins with the incision beingmade (block 102) and the tendon being cut to form the graft 80 (block104). As explained in the previously incorporated '562 application, thegraft 80 may be created from the quadriceps tendon 36, and may include aterminal bone plug formed from the patella.

Once the graft 80 is cut from the quadriceps tendon 36, the cuttingimplement is removed and the first element 52 is threaded through thefirst aperture 62 (block 106), through the hollow portion of the firstelement 52 and out the first handle end 55. Thus, the interiordimensions of the hollow portion of the first element 52 should be sizedso as to accommodate the graft 80 and the bit of patella 82. Likewise,the size of the first aperture 62 should be sufficient to pass both thegraft 80 and the bit of patella 82.

Note that as used herein “threaded through” or similar phrases drawsanalogy to threading a needle, and does not refer to the threads on ascrew.

The graft 80 may then be threaded through the second aperture 72 and thesecond element 54 (block 108 and FIG. 3C). Note that if the apertures 62and 72 are aligned and the second element 54 is already positionedwithin the first element 52, the graft 80 may be threaded through thefirst and second elements 52, 54 concurrently. As is seen in FIG. 3C,the second handle end 64 extends past the first handle end 55. Likewise,at least initially, the apertures 62 and 72 are aligned to allow thegraft 80 to pass therethrough.

The second element 54 is then rotated relative to the first element 52(block 110, FIGS. 3D & 3E). As the two elements 52 and 54 are rotatedrelative to one another, the blade elements 58 and 68 rotate to oneanother and effectively close the aperture through which the graft 80has been passed. This allows the blade elements 58 and 68 to scissortogether, thereby cutting the graft 80. Once the rotation has beeneffectuated sufficiently, the graft 80 is severed (block 112).

The graft 80 is then removed (block 114) as well as the cuttingimplement 50 (block 116, FIG. 3F). Then the graft 80 may be used torepair the ACL as desired.

In an alternate embodiment, the second cutting element may beeliminated. In this regard, an exemplary embodiment of a secondarycutting implement 150 is illustrated in a perspective exploded format inFIG. 5. The secondary cutting implement 150 has a first element 152,which is hollow and has a first handle end 154 and a first distal end156. The first handle end 154 may be encapsulated in a resilientpolymeric annulus 155 which may be textured or knurled to provide asecure grip. The first distal end 156 includes a blade element 158. Theblade element 158 is positioned perpendicular to a longitudinal axis 160of the first element 152. The blade element 158 may be integrally formedwith the body of the first element 152 or fixedly secured thereto. In anexemplary embodiment, the first element 152 is adapted to be reusablewhile the blade element 158 is removably affixed thereto such that itcan be replaced readily. Thus, the blade element 158 may be considereddisposable or reusable as desired. The blade element 158 extends, in anexemplary embodiment, approximately halfway across first distal end 156(e.g., covering approximately 45-55% (and in an exemplary embodimentapproximately 51%) of the area of the first distal end 156) andpartially defines a first aperture 162 through which a bone plug portionof a graft 80 may be threaded as explained above. The first distal end156 further includes a cut out portion which further defines the firstaperture 162. In an exemplary embodiment, the cut out portion is anL-shaped section removed from the cylinder of the body of the firstelement 152. The cut out section may be approximately 25 mm long andremove about 30-50% (and in an exemplary embodiment 49%) of thecircumference of the first distal end 156. The cutout portion providesmore room for the first aperture 162 to accommodate the bone plug.

In an exemplary embodiment, the first element 152 is made from a metalsuch as surgical stainless steel (e.g., made out of chromium, nickel,molybdenum, and/or titanium) such as 316L, 316LVM, and/or compliant withASTM F138. In an alternate embodiment, first element 152 is made from apolymer based material. The blade element 158 may be made from surgicalsteel, glass, obsidian, diamond, or the like as desired. In an exemplaryembodiment, the first element 152 may be approximately 200 mm long.

The secondary cutting implement 150 further includes a second element164, which is hollow and has a second handle end 166 and a second distalend 168. Instead of a cutting element, the second element 164 has ablunt edge 172. The blunt edge 172 is positioned perpendicular to alongitudinal axis 174 of the second element 164. The blunt edge 172 maybe formed from the same material as the body of the second element 164or may be removably affixed to the body. The blunt edge 172 extends, inan exemplary embodiment, approximately half way across second distal end168 (e.g., covering approximately 45-55% (and in an exemplary embodimentapproximately 51%) of the area of the second distal end 168) and atleast partially defines a second aperture 170. The second distal end 168further includes a cut out section, which, in an exemplary embodiment isL-shaped and helps define the second aperture 170. The cut out sectionfacilitates threading the bone plug portion of the graft 80 through thehollow portion of the second element 164. The cut out section may beapproximately 25 mm long

In an exemplary embodiment, the second element 164 is made from a metalsuch as surgical stainless steel (e.g., made out of chromium, nickel,molybdenum, and/or titanium) such as 316L, 316LVM, and/or compliant withASTM F138. In an alternate embodiment, second element 164 is made from apolymer based material. In an exemplary embodiment, the second element164 may be approximately 460 mm long. By design, the second element 164has a smaller radius than the first element 152 such that the secondelement 164 may telescopingly fit within the first element 152.Likewise, by design the first element 152 is shorter than the secondelement 164 such that that the second handle end 166 extends out pastthe first handle end 154 so as to facilitate manipulation of the secondelement 164 within the first element 152.

In addition to first element 152 and second element 164, the secondarycutting implement 150 may further (but optionally) include a thirdelement 176 which is provided to lend stability to the secondary cuttingimplement 150. In particular, the third element 176 may be included suchthat on insertion, the third element 176 closes the cutaway or notchesin the first element 152 and the second element 164, so as to improvecutting when the notches are partially aligned. That is, with the cutouts on the first and second elements 152, 164, there is a point in thecounter-rotation of the elements 152, 164 where the graft 80 is notsupported, which makes cutting the tendon difficult. Thus, the thirdelement 176 may be telescopingly inserted between the first element 152and the second element 164 and provide support for the tendon duringcutting. The third element 176 includes a third handle end 178 and athird distal end 180. The third handle end 178 includes a flange 182that prevents over-insertion of the third element 176 into the firstelement 152 and provides a method of maintaining forward pressure on thefirst element 152 to improve its effectiveness. In an exemplaryembodiment, the third element may be approximately 280 mm long.

FIG. 6 illustrates the secondary cutting implement 150 assembled. Thedistal ends 156, 168 and 180 are all proximate one another as theelements 152, 164, 176 telescopingly fit within one another (secondinside third inside first). The cut outs on the first and secondelements 152, 164 line up and allow the bone plug to pass throughreadily. Additionally, the user may grasp the resilient polymericannulus 155 and the handle end 166 to rotate the first and secondelements 152, 164 relative to one another so as to cause the bladeelement 158 to engage and sever the tendon. The flange 182 may be usedto slide the third element 176 back and forth as needed (i.e., it may beretracted during insertion of the bone plug and tendon and then slidforward once the threading is done and the operator is ready to begincutting).

FIGS. 7-9 illustrate a close up of the distal ends 156, 168, and 180 ofthe first, second and third elements 152, 164, 176 respectively. Aspreviously explained, the blade element 158 is available to interoperateagainst the blunt edge 172 to cut the tendon and the third element 176provides support for the tendon during the cutting.

While the illustrated embodiment has the blade element 158 and the bluntedge 172, these two may be reversed. That is, in such alternateembodiment, the first element 152 has a blunt edge at the first distalend 156 and the second element 164 has a blade element at the seconddistal end 168.

While the present disclosure has focused on the secondary cuttingimplement 150 being used to cut the quadriceps tendon as part of anoperation to repair an injury to an ACL, the present disclosure is notso limited. The secondary cutting implement 150 may be used in othergraft harvesting operations or for other purposes as needed or desired.

Those skilled in the art will recognize improvements and modificationsto the embodiments of the present disclosure. All such improvements andmodifications are considered within the scope of the concepts disclosedherein and the claims that follow.

What is claimed is:
 1. A surgical instrument comprising: a first hollowelement comprising a first longitudinal axis, a first distal end and afirst handle end, the first distal end comprising a first blade elementperpendicular to the fist longitudinal axis; and a second hollow elementcomprising a second distal end and a second handle end, the seconddistal end comprising a blunt edge, the blunt edge perpendicular to thefist longitudinal axis; and wherein the first hollow element is sizedrelative to the second hollow element such that the second hollowelement telescopingly fits within the first hollow element and isadapted to rotate therewithin in such a manner that rotation of thesecond hollow element relative to the first hollow element causes thefirst blade element and the blunt edge to interoperate to cut aworkpiece.
 2. The surgical instrument of claim 1 wherein the firsthollow element is tubular.
 3. The surgical instrument of claim 1 whereinthe second hollow element is tubular.
 4. The surgical instrument ofclaim 1 wherein the first blade element at least partially defines afirst aperture on the first hollow element such that the workpiece maybe threaded through the first aperture and wherein the first aperturecomprises a cut out portion.
 5. The surgical instrument of claim 1wherein the blunt edge at least partially defines a second aperture onthe second hollow element such that the workpiece may be threadedthrough the second aperture and wherein the second aperture comprises acut out portion.
 6. The surgical instrument of claim 1 furthercomprising a third hollow element sized to fit in the first hollowelement.
 7. The surgical instrument of claim 6 wherein the second hollowelement is sized to fit in the third hollow element.
 8. The surgicalinstrument of claim 1 wherein the second hollow element is longer thanthe first hollow element.
 9. The surgical instrument of claim 1 whereinthe workpiece is a quadriceps tendon and the blade elements are adaptedto cut the quadriceps tendon.
 10. The surgical instrument of claim 1wherein the first and second hollow elements are adapted to be insertedwithin a human body.